Multiple-actuator shaker digital control system

Multiple-actuator shaker systems are commonly used in the shock and vibration testing of large test specimens. Structural resonances in the fixturing or test specimen can lead to large inter-actuator or cross-coupling forces which have a degrading effect on the accuracy and stability of the control system. A previous paper formulated the theoretical basis for multiple-actuator-shaker control and reported on an electrohydraulic-shaker digital-control system then under development at Lawrence Livermore Laboratory (LLL). The theoretical basis is reviewed and the implementation and performance characteristics of the completed LLL system are described.